1. Field of the Invention
The present invention relates to an antenna, and more particularly, to an antenna in which a radiator that transmits/receives a frequency signal of a predetermined band and a filter that can control a signal band of an operating frequency of the radiator are integrally formed.
2. Description of the Related Art
An ultra wide band (UWB) communication system is a radio technique that was first developed for military purposes in the 1960's by the U.S. Department of Defense. The UWB communication system is used at a low energy level by using a wide frequency band of 1 GHz to 100 GHz, and a transmission rate thereof reaches up to 500 Mbps to 1 Gbps which is about ten times higher than that of IEEE 802.11a (54 Mbps). The IEEE 802.11a is a set of standards for wireless local area network (WLAN) which is currently considered to have the highest transmission rate.
As to a UWB antenna, a UWB notch antenna has been recently developed, which notches a WLAN frequency band (5 GHz to 6 GHz) in order to avoid interference with the WLAN frequency band.
An antenna and a filter are manufactured as separate devices and are coupled together afterwards. However, for this reason, additional costs are caused for the antenna and the filter, impedance matching must be performed between components, and additional antennal tuning must be made due to changes in antenna characteristics such as reflection loss and group delay.